1983 944 - few questions
Got this car as a project. The bracket for the speed / reference sensor was broken so I purchased a replacement. I believe I have the gap set properly. Because it was broken, I’m not sure what one is the speed or reference in the wiring harness. So I guess that’s question one. I thought I’d be smart and see if one combination gets me injector pulse. I unplugged one injector to see what side has power and what side was ground. (Test light). When I checked, I had power on both sides. I decided to check another and same thing. I swapped the 2 sensors and still the same. Even with the sensors unplugged, still the same. Is this normal for this car? Once I turned key off, then had no power at injectors.
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We have a 944 Handbook page on that here:eccs19 wrote: Wed Apr 22, 2026 3:22 pm Got this car as a project. The bracket for the speed / reference sensor was broken so I purchased a replacement. I believe I have the gap set properly. Because it was broken, I’m not sure what one is the speed or reference in the wiring harness. So I guess that’s question one. I thought I’d be smart and see if one combination gets me injector pulse. I unplugged one injector to see what side has power and what side was ground. (Test light). When I checked, I had power on both sides. I decided to check another and same thing. I swapped the 2 sensors and still the same. Even with the sensors unplugged, still the same. Is this normal for this car? Once I turned key off, then had no power at injectors.
https://www.carpokes.com/app.php/944-sp ... or-testing
The sensor that connects to pins 25 and 26 in the 35-pin DME connector is the ref sensor -- closer to the front of the car in the B position. Speed sensor is toward the rear in the D position and connects to pins 8 and 27.
Is it difficult to pull the connector off, or best to remove the DME from under the dash? I was looking at it (as best as I could) and didn’t see if there’s a tab to pull it off, or if you just grab and pull.Tom wrote: Wed Apr 22, 2026 4:43 pmWe have a 944 Handbook page on that here:eccs19 wrote: Wed Apr 22, 2026 3:22 pm Got this car as a project. The bracket for the speed / reference sensor was broken so I purchased a replacement. I believe I have the gap set properly. Because it was broken, I’m not sure what one is the speed or reference in the wiring harness. So I guess that’s question one. I thought I’d be smart and see if one combination gets me injector pulse. I unplugged one injector to see what side has power and what side was ground. (Test light). When I checked, I had power on both sides. I decided to check another and same thing. I swapped the 2 sensors and still the same. Even with the sensors unplugged, still the same. Is this normal for this car? Once I turned key off, then had no power at injectors.
https://www.carpokes.com/app.php/944-sp ... or-testing
The sensor that connects to pins 25 and 26 in the 35-pin DME connector is the ref sensor -- closer to the front of the car in the B position. Speed sensor is toward the rear in the D position and connects to pins 8 and 27.
SpeedRefTest (1).jpg
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There is a metal latch that you pull back to unclip it. See picture from my Kroon Harness install below...eccs19 wrote: Wed Apr 22, 2026 4:50 pmIs it difficult to pull the connector off, or best to remove the DME from under the dash? I was looking at it (as best as I could) and didn’t see if there’s a tab to pull it off, or if you just grab and pull.Tom wrote: Wed Apr 22, 2026 4:43 pmWe have a 944 Handbook page on that here:eccs19 wrote: Wed Apr 22, 2026 3:22 pm Got this car as a project. The bracket for the speed / reference sensor was broken so I purchased a replacement. I believe I have the gap set properly. Because it was broken, I’m not sure what one is the speed or reference in the wiring harness. So I guess that’s question one. I thought I’d be smart and see if one combination gets me injector pulse. I unplugged one injector to see what side has power and what side was ground. (Test light). When I checked, I had power on both sides. I decided to check another and same thing. I swapped the 2 sensors and still the same. Even with the sensors unplugged, still the same. Is this normal for this car? Once I turned key off, then had no power at injectors.
https://www.carpokes.com/app.php/944-sp ... or-testing
The sensor that connects to pins 25 and 26 in the 35-pin DME connector is the ref sensor -- closer to the front of the car in the B position. Speed sensor is toward the rear in the D position and connects to pins 8 and 27.
SpeedRefTest (1).jpg
Thanks for the help. Will have a look at it tomorrow.Tom wrote: Wed Apr 22, 2026 5:03 pmThere is a metal latch that you pull back to unclip it. See picture from my Kroon Harness install below...eccs19 wrote: Wed Apr 22, 2026 4:50 pmIs it difficult to pull the connector off, or best to remove the DME from under the dash? I was looking at it (as best as I could) and didn’t see if there’s a tab to pull it off, or if you just grab and pull.Tom wrote: Wed Apr 22, 2026 4:43 pm
We have a 944 Handbook page on that here:
https://www.carpokes.com/app.php/944-sp ... or-testing
The sensor that connects to pins 25 and 26 in the 35-pin DME connector is the ref sensor -- closer to the front of the car in the B position. Speed sensor is toward the rear in the D position and connects to pins 8 and 27.
SpeedRefTest (1).jpg
kroon-latch-eampla.jpg
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The early DME boxes might look a little different, but pretty sure that latch is essentially the same...eccs19 wrote: Wed Apr 22, 2026 5:05 pmThanks for the help. Will have a look at it tomorrow.Tom wrote: Wed Apr 22, 2026 5:03 pmThere is a metal latch that you pull back to unclip it. See picture from my Kroon Harness install below...eccs19 wrote: Wed Apr 22, 2026 4:50 pm
Is it difficult to pull the connector off, or best to remove the DME from under the dash? I was looking at it (as best as I could) and didn’t see if there’s a tab to pull it off, or if you just grab and pull.
kroon-latch-eampla.jpg
Your tab for removal worked great and my multi meter got my sensors all sorted. Thanks again.Tom wrote: Thu Apr 23, 2026 10:29 amThe early DME boxes might look a little different, but pretty sure that latch is essentially the same...
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Awesome -- up and running?eccs19 wrote: Thu Apr 23, 2026 3:04 pmYour tab for removal worked great and my multi meter got my sensors all sorted. Thanks again.
It will fire up on starter fluid, but seems to have a fuel delivery issue. Pump runs. Just not sure if actually pumping. The hose going from the tank to the pump is kinked. Not sure if the pump is even mounted in the correct spot. I think I’ll just get a new line and make sure everything is situated correctly and go from there. Probably also replace the filter while I’m at it.
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If you get under there, you can usually at least hear if the pump is running. Also worth pointing out that a short in any one of the injector connectors will prevent all 4 from firing (since they all share a single driver inside the DME). Shaking the harness can sometimes reveal those kinds of problems.eccs19 wrote: Thu Apr 23, 2026 4:30 pmIt will fire up on starter fluid, but seems to have a fuel delivery issue. Pump runs. Just not sure if actually pumping. The hose going from the tank to the pump is kinked. Not sure if the pump is even mounted in the correct spot. I think I’ll just get a new line and make sure everything is situated correctly and go from there. Probably also replace the filter while I’m at it.
